Equipment for forging the cranks of crankshafts in consecutive operations



July 12, 1960 ROBRA 2,944,320

EQUIPMENT FOR FORGING THE CRANKS OF CRANKSHAFTS IN CONSECUTIVEOPERATIONS Filed Feb. 14, 1957 4 Sheets-Sheet 1 FIG. I

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HLROBRA July 12, 1960 2,944,320 EQUIPMENT FOR FORGING THE CRANKS OFCRANKSHAFTS IN CONSECUTIVE OPERATIONS Filed Feb. 14, 1957 4 Sheets-Sheet2 PIC-3.2,

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EQUIPMENT FOR FORGING THE CRANKS CF CRANKSHAFTS IN CONSECUTIVEOPERATIQNS Filed Feb. 14, 1957' 4 Sheets-Sheet 3 l i 9 a a r 1 F 7 7 Ila 4 r i I 1 .5

H i h 0 I Z; i; l6 J 25 46 5 l8 f 27 4. i 25* i 9; 2 W I l in l 1; W 1*-INVEN P H. ROBRA 2,944,320 EQUIPMENT FOR FORGING THE CRANKS OFCRANKSHAFTS July 12, 1960 IN CONSECUTIVE OPERATIONS 4 Sheet s-Sheet 4Filed Feb. 14, 1957 United S a es aten TO 2,944,320 EQUIPMENT FORFORGING THE CRANKS or g rgs nxsnms 1N CONSECUTIVE PERA- Helmut Robra,Mulheim (Ruhr), Germany assignor to Schloemann Aktiengesellschaft,Dusseldorf, Germany Filed eb. 14, 1957, Ser. No. 640,221: Claimspriority, application Germany Feb. 1956 2 Claims. 01. 29-6)" Thisinvention relates to equipment for forging the cranks of crankshafts inconsecutive operations. Such equipment is already known in combinationwith forging presses in which the ram is raised and lowered by the slideandan appliance with a liftable'upperportion is provided for holding thecrankshaft. In such forging equipment the slide of the press is coupledwith a cross beam that can be raised and lowered and contains actuatingmeans such as cylinders and pistons for rapidly raising and lowering theupper part of the holding appliance. The latter must be opened each timea crank has been forged to permit the shaft to be axially advanced by anamount equal to the distance between two neighbouring cranks. Theholding appliance must then be lowered into position again. Such anarrangement has been described in US application No. 482,640 of January18, 1955 and in British application No. 37,689 of December 30, 1954.

This known arrangement leads to structures of considerable height andits operation therefore requires presses of unusual height. It is theobject of the present invention to provide an arrangement that willpermit comparatively low presses to operate crankshaft forging equipmentof the kind that has been described.

The invention consists in that the actuating means such as cylinders andpistons for operating the upper part of the holding appliance arelocated in the slide of the press. The reconstruction of the slide orits replacement when the crankshaft forging appliance is needed isjustified in that it enables forging appliances of the aforesaid type tobe used in a press that is not very high.

In known appliances the upper part of the holding equipment must bealigned with reference to the lower part. This is impossible in anarrangement according to the invention because the movement of the slidewhich is guided between the columns of the press is restricted to awell-defined fixed path and cannot be adjusted with reference to thelower part of the forging appliance.

To overcome this disadvantage it is preferred to provide an arrangementin which the cylinders or pistons act on a cross-beam through anintermediate member 16 with dovetail guides and guideways at rightangles to one another.

Such an arrangement permits the upper part 20, 18 of the holdingappliance to be coupled to the actuating means such as the cylinders 5even though the two parts are relatively slightly out of alignment inthe horizontal direction.

The invention will be more particularly described with reference to anillustrative form of construction shown in the drawings in which:

Figure 1 is a vertical section through holding equipment and parts of aforging press, taken on the line II in Figure 4;

Figure 2 is a section taken on the line IIII in Figure 4;

2,944,320 Patented July 12,1960

Figure Sis a section taken on the line III-III in Figure4; and Figure 4is a plan view of the press. a

The'drawings show parts of afour-column. press, including columns 1,which are secured to a base-plate, not shown, and which support the headmember 2 of-the press. In the head member 2 is a cylinder '32, with aplunger .31 slidable therein. The press'also includes withdrawal pistons33, with cylinders 3-4. The forging equipment according to the inventionincludes a slide 4, with sliding guide members 3 embracing the columns1, the columns, the slide beingconstructed ina'particular way foroperation of the crankshaft forging equipment and this will now bedescribed in greater detail. As shown in Figures 2 and 3 the slidecarries four cylinders 5 arranged to be longitudinally displaceable incylindrical bushings 6 in the slide 4. These cylinders 5 may bedisplaced by hydraulic means to project from the lower end of thebushing 6. To this end, pistons 7 are rigidly secured to the slide 4 byattachment to a crosspiece 8 by means of a nut 9. The crosspiece issecured by nuts 11 and bolts 10 to a supportlz which is rigidlyconnected with the slide 4, for instance by being cast or welded intothe same. A gland 13 seals the piston from the cylinder 5 so thatthecylinder 5 will be forced in the downward direction as soon as ahydraulic or other pressure medium is introduced into the chamber 30.Water introduced into chamber 14 causes the withdrawal of the cylinder5.

As shown in Figure 3 the base of each cylinder is provided with adovetail guide 15 slidably engaged by the corresponding dovetail slot ofan intermediate member 16.' The underside of the intermediate member 16is provided with another dovetail guide 16a which when seen in planextends at right angles to the dovetail guide 15. By means of a key 17 across beam 18 belonging to the crankshaft forging appliance is securedto the dovetail guide 16a. A similar crossbeam 18 is provided on eitherside'of the shaft section from which the crank is to be forged. In amanner known per se the crossbeam 18 carries an upper swage holder 20 ofthe holding appliance in a dovetail slot 19. This swage holder isadapted to bear down on a lower swage holder 21. The latter has a liner21a which supports the die 23 which together with an upper die 22 in theswage holder 20 serves to hold the crankshaft 40 in a central recess 24formed between the two dies.

In dovetail slots 25 and 26 on the slide 4 is a ram' bearer plate 27with a supporting block 27a for the attachment thereto of a ram holder28 with a forked forging ram 29 which forges the cranks on the shaft.The ram can be raised and lowered centrally between the two holdingappliances 1'8, 20, 21.

The foregoing ram 29 is connected with the plunger 31 in the manner thathas been described, that is to say through the intermediary of the slide4. When water is pumped into the cylinder chamber 32 above the plunger31 the descending ram 29 will forge the crank on the shaft. In Figurelthe forging ram 29 is shown in its lowermost position after havingproduced the crank.

' For raising the slide 4 drawback pistons 33 are arranged to slide incylinders 34 in the head of the press. When water is admitted to achamber 35 below the drawback piston 33 the latter will ascend insidethe cylinder 34 and by means of a piston rod 36 withdraw the slide 7 4to which the piston rod is attached.

I claim: 1. In combination with a forging press, equipment for forgingthe crank-throws of crank-shafts, comprising: a

slide movable up and down in the forging press, a forging ram carried bythe slide and movable up and down therewith, lower and upper holdingmembers for holding the crank-shaft that is being forged, the upperholding members being movable up and down relatively to the lowerholdingmernbers, intermediate members located beneath the slide, theseintermediate members being movable up and down relatively to, the slide,cylinder and piston units mounted in the slide, horizontal dovetail slotand guide means connecting the cylinder and piston units with theintermediate members, so that the cylinder and piston units can raiseand lower the said intermediate members relatively to the slide,cross-beams located beneath the said intermediate members, andhorizontal dovetail slot and guide means connecting these crossbeamswith the intermediate members, these slot and guide means being at rightangles to those connecting the cylinder and piston units with theintermediate members, and the upper holding members for the crank shaftbeing carried by the said cross-beams.

2. In combination with a forging press, equipment for forging thecrank-throws of crank-shafts, comprising: a slide movable up and down inthe forging press, a forging ram carried by the slide and movable up anddown therewith, lower and upper holding members for holding thecrank-shaft that is being forged, the upper holding members beingmovable up and down relatively to the lower holding members, cylindersso mounted in the slide as to be vertically displaceable downwards outfrom the slide, cross-pieces located above the slide and rigidly securedthereto, pistons secured to the said cross-pieces and extendingdownwards into the said cylinders, intermediate members located beneaththe slide, these intermediate members being movable up and downrelatively to the slide, horizontal dovetaii slot and guide meansconnecting-the lower-ends of thecylinders with the said intermediatemembers, so that the cylinders eta-operating with the pistons can raiseand lower the said intermediate members relatively to the slide,cross-beams located beneath the said intermediate members, andhorizontal dovetail slot and guide means connecting these -cross beamswith the intermediate members, these slot and guide means being at rightangles to those connecting the cylinders with the intermediate members,and the upper holding members for the crank shaft being carried by thesaid cross-beams.

References Cited in the file of this patent UNITED STATES PATENTS2,534,613 Meley Dec. 19, 19.50 2,747,253 Conchon May 29, 1956 FOREIGNPATENTS 757,526 Great Britain 'Nov. 23, 1953 1,121,589 France May 7,1956

